The device (100') has a modulator that is electrically connected to a power line connection and comprises a signal modulating unit such that a signal to the power line connection is modulated. The determined information in the signal is coded by an electro...

The system (1) has emergency lamps (19, 21, 23, 24) monitored by a lamp monitoring part (32) and attached to radio frequency communication modules (33-39). One of the radio frequency communication modules transfers monitoring data of the lamps in a monitor...